Continuous malolactic fermentation of red wine in a reactor using silica-alginate encapsulated Oenococcus oeni

Malolactic fermentation (MLF) is a challenging and time-consuming step in the wine making process. The effects of climate change are making the intrinsic conditions in red wine more challenging for the growth of lactic acid bacteria through interfering with a prompt and effective MLF. However, this is a necessary process in red wine production that contributes to high quality of wine demanded by consumers. Previous studies in our group reported a highly efficient MLF of red wine by using encapsulated Oenococcus oeni. Here, we designed a bench-scale packed-bed reactor using encapsulated bacteria to facilitate and speed up this process. The time to complete MLF was reduced as the concentration of biocapsules increased. The system exhibited operational stability and efficiency in sequential batches of wine recirculated through the column. Furthermore, an efficient continuous MLF was achieved using the packed-bed reactor. In general, a slight reduction in the concentration of some volatile organic compounds (VOCs) in the wines from the continuous system was observed as compared to those from the recirculated system.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.